Safety car control equipment



July 27, 1937. J, c, MCCUNE v 2,088,530

SAFETY CAR CONTROL EQUIPMENT I Filed May 6, 1936 2 Sheets-Sheet 1 INVENTOR JOSEPH C McCUNE ATTORNEY July 27, 1937. J. c. McCUNE SAFETY CAR CONTROL EQUIPMENT Fild May 6, 1936 2 Sheets-Sheet 2 INVENTOR JOSEPH c. McCUNE ATTORNEY Patented July 27, 1937 UNlE S'l' SAFETY CAR CONTROL EQUIPMENT Application May 6, 1936, Serial No. 78,117

1'7 Claims.

This invention relates to fluid pressure brake systems and more particularly to pneumatic remote controlled safety car equipment.

It is an object of this invention to provide 5 pneumatic remote control safety car equipment that is simple in construction and operation and that requires a minimum of piping.

It is another object of this invention to provide a pneumatic remote control safety car equipment in which a minimum of time is required to effect an application or a release of the brakes.

It is a further object of this invention to provide a brake equipment of the character indicated in which brake cylinder pressure is maintained during the braking operation.

It is a still further object of this invention to provide a brake equipment of the character described in which the car doors can not be automatically opened until after a predetermined brake application has been made.

Other objects and advantages of my invention will be apparent from the following description taken with the accompanying drawings, in which,

Fig. l is a diagrammatic view of apparatus constituting one preferred embodiment of my invention,

Fig. 2 is a detailed plan view showing the foot valve control equipment,

Fig. 3 is a sectional view of a portion of the brake valve device shown in Fig. 1, and

Fig. 4 is a diagrammatic view of the door valve device shown in position to open the car door.

Referring to the drawings, and particularly to Fig. 1 thereof, the brake system comprises a brake cylinder I, that is supplied with fluid under pressure by a control valve device 2 from a main reservoir 3 through a main reservoir pipe 4 as controlled by a brake valve device 5. A door operating valve device 5 is provided for controlling a door engine I for operating the car doors.

The control valve device 2 comprises a casing providing a chamber 8 in one end-of the upper portion thereof, one side of which is bounded by a movable flexible diaphragm 9, and that is in constant communication with a brake pipe H2. The

opposite end of the upper part of the casing which provides a chamber 13 is bounded on one side by a movable flexible diaphragm M, and has constant open communication with the main so reservoir pipe G. A partition wall i5 is provided between the chambers 8 and i3 dividing this space into a chamber i6 that is in open communication with the atmosphere through a port ll, and a chamber l8 that is also in constant open 5 communication with the atmosphere through a port 59. A follower 22 is provided adjacent the inner side of the diaphragm It and is connected by spacing rods 23 to a follower 24 positioned adjacent the diaphragm 9, the followers 22 and it being so spaced by the rods Has to be maintained in continuous contact with the diaphragms it and 5?, respectively, to form a movable diaphragm stack for a purpose to be later described. A stem 25 is provided on the follower 22 at the inner end of which a follower 26 is provided that constantly engages a diaphragm El forming one side of a chamber 28 within the partition wall 55 that is in constant open communication with the brake cylinder l through passage and pipe 29.

The right hand end of thecasing of the control valve device 2 provides an application valve chamber 32 that is closed by a plug 33, and which contains an application valve 3 having a stem 35 extending through a bore in the casing wall and adapted to be engaged by the diaphragm 9 upon movement thereof toward the right. The chamber 32 contains a spring 38 one end of which engages within a cavity in the plug 33, and the other end of which engages the application valve St to bias it to its seat. The application valve chamber '32 is in constant open communication, through passage 31, with a piston chamber 38 of an application relay valve device 39. There is also provided, within the partition I5, a release valve chamber ll closed bya plug 42 between the diaphragm chamber 28 and the chamber M, and containing a release valve 43 having a stem A extending through a bore in the casing wall and adapted to engage the follower 24. A spring i5 is provided within the release valve chamber ll, one end of which engages within a cavity in the plug 12 and the other end of which engages the release valve 33 for urging the valve 43 toward its seat. The release valve chamber M is connected by means of a passage 56 to the application relay valve device 39, to the emergency relay valve device ll, and to the piston chamber of the release relay valve device $8 to be presently described.

In the lower portion of the control valve casing is provided the aforenamed application relay valve device 39, emergency relay valve device 4?, and release relay valve device 48. The application relay valve device 39 comprises the aforenamed piston chamber 38 containing a spring weighted valve piston 49 that is urged by a spring z'i2'upwardly against a rib seat 53 to normally control communication between a chamber 54 that is in constant communication with the main reservoir pipe 4, and a chamber 55 that is in communication through the passage 46 with the release valve chamber H.

The emergency relay valve device il comprises a chamber 56 provided within the casing and containing a spring weighted valve piston 57? that is urged upwardly by a spring 58 provided within the chamber 55 to engage a rib stop 59. A chamber E2 is provided centrally within the valve pisten and contains a spring weighted valve 63 which is urged by the spring it mounted within the chamber 82 upwardly against a rib seat 65 to normally close communication between the chamber 5%, that is in constant open communication with the main reservoir pipe 4, and a chamber 58 that is in constant open communication with the release valve chamber ti through passage iii. As is clearly shown in the drawings, the valve piston 5? has an inwardly extending flange formed thereon and adapted on movement of the valve piston 5? against the spring 58 to engage the periphery of the valve 63 and move it away from the seat rib 55 against the spring 64.

The release relay valve device 58 comprises a piston chamber 6'? provided in the casing and containing a spring weighted valve piston 68 that is urged upwardly by a spring 69 to a rib seat E2 to control communication between a chamber '13 that is in constant open communication with the brake cylinder 2, and a chamber i l that is in constant open communication with the atmosphere through an exhaust port It. A check valve chamber '16 is provided between the passages 36 and 29 and contains a check valve ii for permitting the flow of fluid under pressure from the passage 36 to the passage 28 and to the brake cylinder, and for preventing the flow of fluid under pressure in the reverse direction.

The brake valve device 5 comprises a casing containing a chamber l8 that is in constant open communication with brake pipe and passage l2, and a chamber l9 that is in constant open communication with main reservoir passage and pipe 4, and between which is positioned a diaphragm stack comprising a diaphragm 82, forming one wall of the chamber i8 and a follower 83 adjacent thereto that is attached in spaced relation by rods 84 to a follower 35, that is adjacent a diaphram 8i comprising one wall of the chamber H. The rods E l for spacing the followers 83 and 86 extend through bores in a partition wall 85 in the casing structure.

A brake pipe charging valve chamber 88 is provided above the diaphragm stack and is in constant communication with the main reservoir passage and pipe 4, and contains a brake pipe charging valve 89 having a stem 92 extending through a bore in the casing into the chamber 1 8 to engage the diaphragm $2. The outer side of the chamber 88 is closed by a cap 93 having a cavity therein for receiving one end of a spring 95, the lower end of which engages the valve 89 to urge it toward its seat. A release Valve chamber 95 is provided within the partition 85 and contains release valve 96 having a stem 91 extending upwardly through a bore in the casing wall and adapted to engage the follower B3. The lower side of the chamber 95 is closed by a cap 98 having a cavity therein for accommodating one end of a spring 99, the upper end of which engages the valve 95 and urges it toward its seat. A space between the partition 85 and the diaphragm 82 provides a chamber m2 that is in constant open communication with the atmosphere through an exhaust port H33 and. which contains a spring M4, the lower end of which engages the partition 85 and the upper end of which engages the follower plate 83 to urge the diaphragm stack upwardly.

To provide for manual movement of the diaphragm stack a lever m5 is provided, one end of which is pivoted on the pin M6 mounted on the casing, and the other end of which is adapted to be moved by a rod till that extends upwardly through the brake valve casing structure and terminates in an operating button 08. The lever N35 is connected to the diaphragm stack by means of a member ms pivoted to the lever I05 by a pin HE and adapted to engage the upper end of a spring iii, the lower end of which engages within a cavity in the follower plate 86.

An emergency mechanism is provided on the brake valve device 5 comprising a rod H2 extending downwardly within the casing and provided with a heel rest M3 on the upper end thereof. The lower end of the rod HZ engages the upper end of a spring H4 provided Within a bore in the casing structure, and the lower end of which engages an emergency valve l 55 for controlling communication between a chamber H6 that is in constant communication with the brake pipe and a chamber H'i that is in constant communication with the atmosphere through an exhaust port H3. It is necessary upon charging the system to maintain pressure on the heel rest H3 to prevent an emergency application of the brakes.

Locking means are provided on the brake valve device for preventing an emergency application of the brakes after a service application thereof should pressure be thereafter released from the heel rest H3. This lock comprises a cam H9 provided within a chamber I22 in the casing structure and having a cam face #23 on the under side thereof for engaging a notch 524 on the rod lfll to hold the rod in its lower or brake applying position, and a cam face I25 on the upper side thereof for engaging the operating end i26 of a lever 12? mounted on a pin I28, and provided with a bifurcated end for engaging a pin E32 extending through the rod H2. A shaft I33 having an operating handle 534 is provided for actuating the cam iii which may be actuated to urge the rod Hill downwardly to effect a service application of the brakes, and to actuate the lever i2? in a counter-clockwise direction to increase the pressure on the spring 5 M and maintain the emergency valve 1 i5 seated so as to prevent an emergency application of the brakes during said service application thereof.

A switch is provided on the brake valve device comprising a movable contact member 135 for engaging fixed contact members 38 and I31, and normally urged into engagement therewith by a spring I38 to close a circuit from the overhead trolley I39 through conductor M2, switch contact members I36, I35 and H51, and the winding of a relay I43 to ground at M4 to maintain the relay energized and in its upper or circuit closing position. In this position of the relay, trolley voltage is brought from the trolley l39 through conductor 35 and relay contact member M6 to the manual controller Hill, which, when the controller is in a motoring position, closes a circuit through the car motor M8 to ground at 169 to supply power for driving the car. When the lock device is moved to a position to hold the manually operable member in! in a brake applying position and the emergency valve H5 seated, the right hand end of the lever I52 is forced downwardly by the face I23 of the cam H9, thus rotating the lever I52 in a clockwise direction about the pin I28, and moving the left hand end upwardly to move the switch contact member I35 by means of the connecting rod I53 against the bias of the spring I33 to a circuit interrupting position to deenergize the relay l 43 and permit the contact Mt to drop to its open or circuit interrupting position to prevent the supply of power to the motor I58.

The door operating valve device 5 comprises a body portion I56 and a bracket portion I55. The body portion comprises a casing defining a valve chamber Ifit that is in constant communication with the main reservoir passage and pipe and contains a rotary valve I51 that is adapted to be operated by a handle I58, and is provided with a cavity I53 on the face thereof for connecting a door closing pipe and passage I62 to the main reservoir passage and pipe I in a manner to be later described.

The bracket portion 855 of the door valve device comprises a casing providing a piston chamber I61 that is in constant open communication with the brake passage and pipe I2, and which contains a spring weighted piston I 53 that is forced downwardly by a spring I 59 into engagement with a rib seat I'IZ, the spring ltd surrounding the main body portion of the piston I68, the lower end engaging a shoulder Ilfi there on and the upper end engaging the upper wall of the chamber NW. A door interlock valve chamber I66 is also provided within the casing, and contains a door interlock valve Ils having a stem I'M extending upwardly therefrom through a bore in the lower part of the piston I63 into a chamber in the central portion of the piston, and which contains a spring I'I5 surrounding the stem I'M, the lower end of which engages the'inner wall of the central chamber, and the upperend of which engages a head I75 carried by the valve stem I'M for biasing the valve and stem upwardly. A spring IT! is provided about the lower portion of the stem I'M, the upper end of the spring engaging the under side of the piston I 68, and the lower end of the spring engaging the valve I13. When the piston I68 is in its illustrated position in contact with the rib seat I I2, the force of the spring HT is greater than that of the spring I15, thus forcing the valve I13 downwardly into engagement with the valve seat I78 to close communication from the passage I65 to the atmosphere through the exhaust port III The door engine I for operating the entrance and exit doors of the car comprises a casing I82 providing a piston chamber I33 containing a piston I84 therein that is provided with a stem I85 having a piston I86 thereon of less diameter than the piston I8 2, and adapted to operate within a bore I81, and one side of which is open to the atmosphere. An operating rod I88 is connected with the piston stem I85 and is pivotally connected to operate mechanism (not shown) for opening and closing the car doors. A chamber I89, provided between the pistons Iild and I85 is in constant open communication with the brake pipe I2 Fluid under pressure is normally supplied to the piston chamber I83 through the door valve device 6. When, however, the'chamber I88 is vented in a manner to be hereinafter described,

the greater fluid pressure within the chamber I89 acting on the left face of the piston I8 3 causes the piston to move to the right to eiiect the opening of the car doors.

Charging the system 4 to the door valve device 6 charging the valve chamber I56 and the door interlock valve chamber I66, thus building up pressure on the under side of the door interlock valve piston I68. From the valve chamber I56 fluid under pressure flows through passage I65, check valve chamber I M, passage I63 and the cavity I55 in the rotary valve I57, through passage and pipe I62 to charge the piston chamber I83 of the door engine I, thus maintaining the piston I84 in its illustrated or door closing position. Fluid under pressure also flows from the passage I55 through passage I92 to a port in the valve seat below the rotary valve I51. Fluid under pressure also flows from the main reservoir pipe 4 to charge the diaphragm chamber IS on the foot valve device 5, and to the brake pipe charging valve chamber 9E3.

As the diaphragm chamber '19 is charged, the diaphragm stack comprising the diaphragms 31 and 82 tog ther with the followers 85 and 83 is forced upwardly by the pressure on the under side of the diaphragm 8T aided by the pressure of the spring I64 on the under side of the follower 85, thus releasing the pressure of the follower 83 on the stem 97! and permitting the release valve 95 to be forced to its seat by the spring 99, and forcing the brake pipe charging valve 39 upwardly from its seat to permit the flow of fluid under pressure from the chamber at through the boreBI into the diaphragm chamber I8 and to the brake passage and pipe I2. During charging of the brake pipe Iii and thereafter it is necessary that the operator maintain pressure on the: heel rest M3 to prevent dead man emergency application of the brakes.

Fluid under pressure from the brake pipe I2 flows to the piston chamber I89 of the door en gine device I, and to the interlock piston chamber I6? of the door valve device 6, charging these chambers. Fluid under pressure also flows from the brake pipe I2 to the control valve, device 2 to charge the piston chamber 55 of the emergency relay, and to charge the diaphragm chamber I5. As the diaphragm. chamber I 3 is charged from the main reservoir pipe 4, the diaphragm stack comprising diaphragms it, ill and 9 is moved toward the right against the bias of the spring 35, permitting the valve 33 to be seated by the spring t5, the diaphragm 9 engaging the stem of the release valve 3d and forcing the valve from its seat against the bias of the spring 36 to permit the flow of fluid under pressure from the diaphragm chamber 8 to the release valve chamber 32, and therefrom through passage 37 to the piston chamber 38 on the under side of the application valve piston 69. When the pres-v .ciently to permit release valve 38 to beseated by the spring 36 to close communication from the diaphragm chamber-8 to the pistonchamb'er sit, .and :to unseat =theivalve '53 .to again open communication from; the chamber M to the atmosphere. A small passage I92 through the application relay piston 49 permits the complete equalization of pressures on the two faces of the piston, the piston being held to its seat by the pressure of the spring 52. Likewise, the emergency relay valve piston 57 is normally held to its seat by the force of the spring 58 plus the force of fluid under pressure at brake pipe pressure within the piston chamber 56 urging the piston upwardly against the main reservoir pipe pressure within the chamber 56.

It will be noted that the diaphragm stack of the foot valve device 5 is forced upwardly by the main reservoir pipe pressure within the chamber 79 acting against the diaphragm Bl, and also by the force of the spring 584, so that the downward pressure on the diaphragm 82 within the chamber 73 will not become sufficient to cause the brake pipe charging valve 39 to seat by the brake pipe pressure alone so that the brake pipe is charged to main reservoir pipe pressure.

Operation When the operator wishes to apply the brakes, he presses his foot down on the button I88 to lower the button and the rod it? an amount depending upon the desired degree of application of the brakes. The rod l8! and the lever [05 are thus forced downwardly to cause a compression of the spring Hi to effect a downward force on the follower 86 of the diaphragm stack corresponding to the amount of compression of the spring. This downward force on the diaphragm stack, in addition to the pressure within the chamber '38 acting downwardly on the diaphragm 82, causes the diaphragm stack to move downwardly to permit the seating of the brake pipe charging valve 89, and to force the valve 98 from its seat against the bias of the spring 99 to eifect a reduction in brake pipe pressure by the flow of fluid under pressure from the brake pipe through valve chamber 95, past the unseated valve 95 to the atmosphere through chamber H32 and exhaust port E93. The reduction in brake pipe pressure, for any given position of the button 898 and rod 1M, will continue until the pressure within the chamber 18, plus the pressure of the spring 5 l I, has been reduced to slightly less than the upward pressure of the spring Hit, plus the upward pressure within the chamber 18 against the diaphragm 81, which upward pressure forces the diaphragm stack upwardly topermit the valve $36 to seat.

Upon the reduction in brake pipe pressure, the pressure within the diaphragm chamber 8 of the control valve device 2 is correspondingly reduced, thus disturbing the balance of pressures on the diaphragm stack and permitting the diaphragm stack to move toward the right to permit the seating of the valve &3 to close communication from the central chambers 55 and 68 above the application relay piston i9 and the emergency relay piston 57, respectively, and from the release relay piston chamber 67 to the atmosphere through passage 46, chamber i8 and port l9. Upon the movement of the diaphragm stack toward the right, the diaphragm 9 engages the stem of the application valve 3t, thus forcing the valve 34 from its seat and permitting a reduction in pressure within the piston chamber 38 of the application relay valve device tobrake pipe pressure. Upon a predetermined slight decrease in pressure within the chamber 38, the upward force of the spring 52 plus the pressure within the chamber 38 against the valve piston 49 becomes less than the downward force of pressure within the chamber 54 around the outer rim of the piston 49, thus forcing the piston 49 downwardly and permitting the flow of fluid under pressure from main reservoir pip-e 4 through chamber 55, passage it to the piston chamber 6? of the release relay valve device, and past the unseated check valve ll, through the passage and pipe 29 to the brake cylinder I. As pressure builds up within the brake cylinder l, pressure correspondingly builds up within the chamber 13 above the release relay piston 68, which is held to its seat by the pressure within the piston chamber 61 plus the pressure of the spring 69. Pressure at brake cylinder pressure also builds up within the diaphragm chamber 28 located centrally of the diaphragm stack of the control valve device 2, creating a force on the diaphragm 21 tending to move the diaphragm stack toward the left, which pressure at some predetermined brake cylinder pressure becomes sufiicient to move the diaphragm stack sufficiently to permit the seating of the valve 34, thus permitting an equalization of the pressures on the two sides of the application relay piston 49 by the flow of fluid under pressure from the chamber 54 into the piston chamber 38 through the small port I92 in the piston. The piston 49 will thus be forced upwardly to its seat by the P spring 52, closing communication from the main reservoir pipe 4 to the brake cylinder I.

If, for any reason, fluid under pressure leaks from the brake cylinder after an application of the brakes causing a reduction in brake cylinder pressure, a corresponding reduction in pressure takes place in the diaphragm chamber 28, thus reducing the force on the diaphragm 2'? tending to force the diaphragm stack toward the left and permitting the diaphragm stack to move toward the right an amount sufficient to again unseat the valve 34, and cause movement of the valve piston 49 from its seat to supply further fluid under pressure to the brake cylinder until the pressure in the brake cylinder and the diaphragm chamber 28 is sufficient to again cause the valve 34 to seat. It will thus be seen that the control valve 2 operates to maintain brake cylinder pressure at a value corresponding to the reduction in brake pipe pressure by automatic operation of the diaphragm stack.

When the operator wishes to release the brakes, pressure is released from the button Hi8, thus allowing the lever N15 to move upwardly and release the downward pressure of the spring I l i on the follower 86. The diaphragm stack of the control valve device thus moves upwardly because the pressure within the chamber ":79 acting on the diaphragm 8?, plus the pressure of the spring 34, is greater than the pressure Within the chamber 18 acting on the diaphragm 82. Upon this upward movement of the diaphragm stack, the diaphragm 82 engages the stem 92 of the brake pipe charging valve 89, forcing it upwardly from its seat and permitting the flow of'fluid under pressure from the main reservoir pipe l to the brake pipe 52, as above described for charging the system. 1 As the pressure within the brake pipe builds up, the pressure correspondingly builds up within the diaphragm chamber 8 of the control valve device 2, thus forcing the diaphragm stack toward the left, the follower 24 engaging the stem M of the brake cylinder exhaust valve 43, which is forced toward the left against the bias of the spring 45,.to effect the release of fluid under pressure from the piston chamber 61 of the release relay valve device through passage valve chamber ill, chamber I8 and exhaust port I9. The check valve 11 prevents fluid at brake cylinder pressure from flowing into the piston chamber 61, and the pressure within the chamber 13 on the upper side of the piston 68 forces the piston 68 downwardly against the bias of the spring 652 to effect the rapid venting of the brake cylinder through chamber 1t and exhaust port 35 until the pressure has been re duced sufiiciently to permit the piston 68 to be forced to its seat 12 by the spring 553. Thereafter the brake cylinder is maintained in communication with the atmosphere through the small open ing 993 in the piston 58, passage is, and past the unseated brake cylinder release valve (I3.

To efiect a dead man emergency application of the brakes, pressure is released from the heel rest H3 of the brake valve device 5, permitting the rod H2 to be forced upwardly by the rod spring H4, and relieving pressure on the spring II l that normally holds the emergency valve M to its seat. The emergency valve H5 is, therefore, unseated by brake pipe pressure to effect the release of fluid under pressure from the brake pipe 22 through exhaust port lit to efiect a rapid reduction in brake pipe pressure. During the upward movement of the rod M2, the pin I32 therein (see Figs. 1 and 3) engages the under side of lever $52 and raises the switch contact member 135 to a circuit interrupting position to interrupt the supply of power to the motor M8 independently of the position of the controller Upon the reduction in brake pipe pressure, the diaphragm stack of the control valve device 2 comprising diaphragrns I l, 21 and 9 operates in the manner above described under service application of the brakes to eifect the supply of fluid under pressure to the brake cylinder. The emergency relay piston 51 is also moved downwardly against the bias of the spring 58 upon a suflicient reduction in brake pipe pressure resulting in a corresponding reduction in the pressure within the piston chamber 58. On this movement of the valve piston 51, the valve 53 is moved away from the seat rib 65, as explained above, thus also effecting the supply of fluid under pressure past the unseated valve 63 through chamber 66, passage past the check valve 11 to the brake cylinder I. The spring 58 on the under side of the emergency relay piston 51 is designed to create a relatively strong upward force on the piston to prevent its unseating until a substantial reduction in brake pipe pressure has been effected, or considerably in excess of the reduction required in the chamber 38 to cause the piston 49 of the application relay valve device 39 to move from its seat. By virtue of the relatively strong force exerted by the spring 58, the piston 51 is moved upwardly again upon a relatively small increase in brake pipe pressure, thus forcing the valve 63 to its seat 65 to prevent the flow of fluid under pressure from the main reservoir pipe 4 through chambers 56 and 66, passage 46, valve chamber ll, and chamber 18 to the atmosphere as might happen should the piston 51 of the emergency relay valve device remain unseated after the diaphragm stack of the control valve device 2 has been moved to release position.

By means of the lock comprising the operating handle I 34 and the cam H9 it is possible to lock the brake valve device 5 in service application position by holding the rod Ill! in any desired position by the cam I I9, the lever I21 holding the heel rest I I 3 in its lower position, to maintain the valve H5 seated. At the same time the cam H9 operates the switch element I35 to its circuit interrupting position, thus interrupting the power supply to the car motor I48. This locking mechanism may be employed to prevent an emergency application following a service application, such as while changing over the control of the car from one end to the other, it being impossible to start the car from one end while the locking mechanism at the opposite end is in the locked position, since a service application of the brakes will be maintained and the power supply to the motors will remain interrupted.

When the operator wishes to open the car doors, the handle wt of the door valve device 6 is moved from the position shown in Fig. l to the position shown in Fig. 4, bringing a cavity I95 in the rotary valve I51 (see Fig. 4'.) to a position to effect communication between the passages ItZ and 1192, thus connecting the piston chamber I83 of the door engine 1 to the valve chamber Hi6 of the interlock valve device. Should this operation of the door valve I51 be made prior to a sufficient reduction in brake pipe pressure tov move the interlock valve H3 from its lower seat, the door engine will not be operated since the chamber 583 is prevented from being vented by the seated interlock valve I13. If, however, a suflicient reduction in brake pipe pressure has been effected so that the pressure in the piston chamber I $1, plus the downward force of the spring I69, is less than the force of fluid under pressure at main reservoir pipe.

to the valve chamber I66; thus-preventing the venting of the, main reservoir pipe.

When the piston chamber its is vented through exhaust port I19, as above described, the greater pressure within the piston chamber lBB-forces the piston i3 1 together with the stem I85 and the connecting rod I38 toward the right, the rod I 88 operating the door mechanism, not shown, to open the car door. When the rotary valve I51 is in the position illustrated in Fig. 4, a port H96 therein connects the valve chamber I56, which is maintained at main reservoir pressure, to the atmosphere through a restricted exhaust port I91, thus giving a warning tothe operator that the handle I 58 is in the door opening position. Upon an increase in brake pipe pressure to release the brakes, a corresponding increase in pressure in the piston chamber itl of the door interlock valve device 8 causes the piston I68 to be forced downwardly, moving the valve M3 to its lower valve seat I18, as illustrated in Fig. 1, thus closing communication from the valve chamber I66 to the atmosphere through the exhaust port I19, and again efiecting communication from the main reservoir pipe t to the valve chamber I 66 and the passage I65 through which fluid under pressure flows to the piston chamber I83 of the door engine, either through passage I63 and cavity I59 of the rotary valve I51, if the rotary valve is in the position illustrated in Fig. 1, or through the passage I92 when the rotary valve is in the position illustrated in Fig. 4, thus effecting movement of the piston I84 and the rod I88 toward the left to effect the closing of the car door.

A ball check valve 5% is shown Within a chamber Hid in the door valve device 6, which, when the interlock valve H3 is unseated from its lower seat M8 to vent the valve chamber and the passage W5, is moved by the greater pressure on the brake pipe side of the ball check i99 toward its left seat to close communication between the passages 563 and 565 to prevent the piston chamber l83 of the door engine I from being vented through cavity E59 of the door valve device when In the position illustrated in Fig. 1. Thus upon a reduction in brake pipe pressure, the pressure in the piston chamber I83 may be correspondingly reduced, but is permitted to be reduced only to brake pipe pressure so long as the valve I5? is in the position illustrated in Fig. 1. In the case of emergency application of the brakes wherein the brake pipe pressure is reduced substantially to zero pressure, a corresponding reduction in the pressure in the piston chamber E83 is permitted, thus eliminating fluid pressure on both sides of the piston I84 of the door engine, thus permitting the door to be opened by hand without any resistance due to fluid pressure in the door englue 1.

It will be apparent to those skilled in the art that many modifications in the apparatus illustrated and described may be made without departing from the spirit of my invention and I do not wish to be limited otherwise than by the scope of the attached claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a brake equipment for vehicles, in combination, a brake cylinder, 21 control valve device for controlling the supply of fluid under pressure to said brake cylinder and having three spaced movable abutments operatively connected to move in unison, two of said abutments being substantially equal in area, and the third abutment having substantially less area than either of the others, means for supplying fluid under pressure at substantially constant pressure to one side of one of said two abutments, means for normally supplying fluid under pressure to one side of the other ofv said two abutments at a substantially constant pressure, and means responsive to a reduction in pressure on said last defined abutment for efiecting the supply of fluid under pressure to said brake cylinder and to said third abutment at brake cylinder pressure, said abutments being movable in response to build up in brake cylinder pressure to out 01f the further supply of fluid under pressure to said brake cylinder.

2. In a brake equipment for vehicles, in combination, a brake cylinder, a control valve device for controlling the supply of fluid under pressure to said brake cylinder and having three spaced movable abutments operatively connected to eflect corresponding movements thereof, means for supplying fluid under pressure to two of said abutments to develop balanced opposing forces, the third of said abutments having substantially less area than either of the others, biasing means for urging said abutments to a brake releasing position, said abutments being movable upon a reduction in pressure on ene of said above described abutments to a position to effect the supply of fluid under pressure to said brake cylinder and to one side of said third abutment to aid said biasing means, and, upon a predetermined brake cylinder pressure dependent upon the reduction aosaeso in pressure on one of said abutments, to effect the movement of said abutments to a position to cut off the flow of fluid under pressure to said brake cylinder.

3. In a fluid pressure brake system, in combination, a first movable abutment constituting one wall of a chamber subject to fluid under pressure supplied to a first chamber, a second movable abutment constituting one wall of a chamber subject to fluid under pressure supplied to a second chamber, a third movable abutment constituting one wall of a chamber subject to fluid under pressure supplied to a third chamber according to the degree of application of the brakes, each abutment constituting a Wall of one only of said chambers, means for interconnecting said three abutments to effect corresponding movement-s thereof according to the differential pressures in said three chambers, the pressure in said second and third chambers opposing the pressure in said first chamber, and means actuated upon movement of said abutments in response to a reduction in pressure in said second chamber for effecting an application of the brakes to a degree corresponding to the amount of reduction in pressure in said second chamber as determined by I the pressure in said third chamber.

4. In a fluid pressure brake system, in combination, a brake cylinder, a main reservoir, a pipe normally charged with fluid under pressure supplied from the main reservoir, a normally charged brake pipe, a control valve device having a first movable abutment subject on one side to atmospheric pressure and on the other to main reservoir pipe pressure, a second movable abutment subject on one side to atmospheric pressure and on the other to brake pipe pressure, a third movable abutment subject on one side to atmospheric pressure and on the other to brake cylpressure, means for interconnecting said three abutments to effect corresponding movements thereof in accordance with the pressures on said three abutments, the pressures on said second and third abutments opposing the pressure on said first abutment, and valve means responsive to a reduction in pressure on said second abutment for efiecting the supply of fluid under pressure from said main reservoir pipe to said :rake cylinder, and responsive to the build in pressure in said brake cylinder and against said third abutment depending upon the reduction in pressure on said second abutment for moving said valve to lap position.

5. In a fluid pressure brake system, in combination, a brake cylinder, a normally charged main reservoir pipe, a normally charged brake pipe, a control valve device having a chamber subject to fluid under pressure at main reservoir pipe pressure and having a movable abutment forming one wall thereof, means for opposing the force of said abutment comprising a spring biasing means, a movable abutment forming one wall of a chamber supplied with fluid under pressure at brake pipe pressure, and a chamber supplied with fluid under pressure at brake cylinder pressure and having one movable wall only constituting an abutment, valve means subject to joint movement of said abutments in response to a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder and to said last named chamber to efiect an application of the brakes in accordance with the amount of reduction in brake pipe pressure.

6. In a fluid pressure brake system, in combination, a brake cylinder, a normally charged sition to said first named abutment, an application relay for controlling the supply of fluid under pressure to said brake cylinder and a release relay for controlling the release of fluid under pressure from said brake cylinder, valve means actuated by said abutment upon a reduction in brake pipe pressure for effecting operation of said application relay to apply the brakes and upon an increase in brake pipe pressure for effecting the operation of said release relay to release the brakes, and an emergency relay operable upon a predetermined reduction in brake pipe pressure for eflecting the supply of fluid under pressure to said brake cylinder independently of said valve means.

'7. In a brake system for vehicles, in combination, a brake cylinder, a brake pipe, a control valve device responsive to brake pipe pressure and operable to effect an application of the brakes to an extent dependent upon the degree of reduction in brake pipe pressure, a door engine for operating a car door, a manually controllable door valve device for controllin said door engine, and an interlock valve device subject to brake pipe pressure and movable to prevent operation of said door engine to door opening position by said door valve device and operative only upon a predetermined reduction in brake pipe pressure to permit said operation of the door engine.

8. In a brake system for vehicles, in combination, a brake cylinder, a brake pipe, a control valve device responsive to brake pipe pressure and operative to eflect an application of the brakes in accordance with the reduction in brake pipe pressure below a predetermined value, a door engine having a piston chamber containing a piston operable to a door closing position upon the supply of fluid under pressure to said chamber and to a door opening position upon the venting of fluid under pressure from said chamber, a door valve device for controlling the supply of fluid under pressure to and the release of fluid under pressure from said piston chamber, and an interlock valve device for preventing the release of fluid under pressure from said chamber by said door valve device when in a door opening position and operative only upon a predetermined reduction in brake pipe pressure to permit the venting of fluid from said chamber.

9. In a brake system for vehicles, in combination, a brake cylinder, a brake pipe, a control valve device responsive to brake pipe pressure and operable to eflect an application of the brakes in accordance with a reduction in brake pipe pressure below a predetermined value, a door engine having a movable abutment subject on one side to main reservoir pipe pressure for actuating the abutment to a door closing position and subject on the other side to brake pipe pressure for actuating the abutment to a door opening position when fluid under pressure is vented from the first named side of the abutment, a door valve for controlling the supply of fluid under pressure to and the release of fluid under pressure from said first named side of said abutment, and an interlock valve device subject to brake pipe pressure for preventing the release of fluid under pressure from the first named side of said abutment when the door Valve device is in a door opening position until a predetermined reduction in brake pipe pressure has attained.

10. In a brake system for vehicles, in combination, a brake cylinder, a brake pipe, a main reservoir pipe, a control valve device responsive to brake pipe pressure and operable to effect an application of the brakes in accordance with a reduction in brake pipe pressure below a predetermined value, a door engine having a movable abutment subject on one side to main reservoir pipe pressure for actuating the abutment to a door closing position and subject on the other side to brake pipe pressure for actuating the abutment to a door opening position when fluid under pressure is vented from the first named side of the abutment, a door valve for controlling supply of fluid under pressure to and the release of fluid under pressure from said first named side of said abutment, an interlock valve device having a valve and spring Weighted piston subject on one side to brake pipe pressure and on the other side to main reservoir pressure and operable above a predetermined brake pipe pressure to close communication from said first named side of said abutment to atmosphere through said door valve device when in a door opening position, and

upon a predetermined reduction in brake pipe pressure to open said communication. I

11. In a brake system for vehicles, in combination, a brake cylinder, a brake pipe, a main reservoir pipe, a control valve device responsive to brake pipe pressure and operable to effect an application of the brakes in accordance with a reduction in brakepipe pressure below a predetermined value, a door engine having a movable abutment subject on one side to main reservoir pipe pressure for actuating the abutment to a door closing position and subject on the other side to brake pipe pressure for actuating the abutment to a door opening position when fluid under pressure is vented from the first named side of the abutment, a door valve for controlling the supply of fluid under pressure to and the release of fluid under pressure from said first named side of said abutment, an interlock valve device subject to the diflerence in main reservoir pipe pressure and brake pipe pressure for closing communication from the first named side of said abutment tothe atmosphere through said door valve device when in a door opening position until a predetermined reduction in brake pipe pressure has attained, a check valve in said door valve device subject to brake pipe pressure and the pressure applied to said first named side of said abutment for permitting a reduction in pressure thereinto, but not below, brake pipe pressure when the door valve device is in its door closing position.

12. In a brake equipment for vehicles, in combination, a brake cylinder, 2, main reservoir pipe normally charged with fluid under pressure, a brake pipe normally charged with fluid under pressure, means for controlling brake pipe pressure comprising a brake valve device having a pair of spaced movable abutments connected by a common stem to effect corresponding movements thereof and subject respectively to main reservoir pipe and brake pipe pressures and valve means operated by said abutments for controlling the supply of fluid under pressure from said main reservoir pipe to said bra :e pipe and from said brake pipe to the atmosphere, a control valve device responsive to brake pipe pressure and operable to effect a supply of fluid under pressure to said brake cylinder in accordance with a reduction in brake pipe pressure below a predetermined value, a door engine for operating a car door, a manually controlled door valve device for controlling the door engine, and an interlock valve subject to brake pipe pressure and operative to prevent operation of said door engine by said door valve device when the brake pipe pressure is above a predetermined value.

13. In a brake equipment for vehicles, in combination, a brake cylinder, a main reservoir pipe normally charged with fluid under pressure, a brake pipe normally charged with fluid under pressure, means for controlling brake pipe pressure comprising a brake valve device having a pair of spaced movable abutments connected by a common stem to effect corresponding movements thereof and subject respectively to main reservoir pipe and brake pipe pressures and valve means operated by said abutments for controlling the supply of fluid under pressure from said main reservoir pipe to said brake pipe and from said brake pipe to the atmosphere, a control valve device responsive to brake pipe pressure and operable to effect the supply of fluid under pressure to said brake cylinder in accordance with a reduction in brake pipe pressure below a predetermined value, a door engine having a piston chamber containing a piston and operable to a door closing position upon the supply of fluid under pressure to said piston chamber and to a door opening position upon the venting of said chamber, a door valve device for controlling the supply of fluid under pressure from and to said piston chamber and an interlock valve device for preventing the venting of said piston chamber by said door valve device when in a door opening position if the brake pipe pressure is above a predetermined amount.

14. In a brake equipment for vehicles, in combination, a brake cylinder, a main reservoir pipe normally charged with fluid under pressure, a brake pipe normally charged with fluid under pressure, means for controlling brake pipe pressure comprising a brake valve device having a pair of spaced movable abutments connected by a common stem to effect corresponding movements thereof and subject respectively to main reservoir pipe pressure and brake pipe pressure and valve means for controlling the supply of fluid under pressure from said main reservoir pipe to said brake pipe and from said brake pipe to the atmosphere, a control valve device responsive to brake pipe pressure and operable to effect the supply of fluid under pressure to said brake cylinder in accordance with a reduction in brake pipe pressure below said predetermined value, means for operating a car door comprising a chamber normally charged with fluid under pressure, a manually operable valve for venting said chamber to effect movement of said operating means to a door opening position, and automatic means for preventing the venting of said chamber by said manually operable means.

15. In a brake equipment for vehicles, in combination, a brake cylinder, a control valve device for controlling the supply of fluid under pressure to said brake cylinder and having three spaced movable abutments operatively connected to move in unison, one of said abutments being subject only to a substantially constant fluid pressure, another of said abutments being subject only to brake pipe pressure, and the third of said abutments being subject only to brake cylinder pressure, and means responsive to movement of said abutments upon a reduction in brake pipe pressure for eifecting the supply of fluid under pressure to said brake cylinder and to said third abutment at brake cylinder pressure, said abutments being movable in response to build up in brake cylinder pressure to cut off the further supply of fluid under pressure to said brake cylinder.

16. In a brake equipment for vehicles, in combination, a brake pipe, a brake cylinder, a control valve device for controlling the supply of fluid under pressure to said brake cylinder and having a plurality of chambers each having one movable wall only forming a movable abutment, two of said abutments being subject, respectively, to the pressure of the brake pipe and a substantially constant fluid pressure arranged in position, and one abutment being subject to the pressure of fluid supplied to the brake cylinder, and means operated by said abutments upon a reduction in brake pipe pressure for supplying fluid under pressure to the brake cylinder, said means being operated by said abutments upon an increase in brake cylinder pressure to cut ofl the further supply of fluid under pressure to said brake cylinder.

17. In a brake equipment for vehicles, in combination, a brake pipe, a brake cylinder, a control valve device for controlling the supply of fluid under pressure to said brake cylinder and having two movable abutments of substantially equal area arranged to exert opposing forces and subject, respectively, to brake pipe pressure and a substantially constant fluid pressure, said abutments being held in spaced relation by rods .connecting points adjacent their peripheries, an intermediate abutment contained in the space between said above named two abutments and operatively connected to move therewith, said intermediate abutment being subject to the pressure of fluid supplied to the brake cylinder, means operated by said abutments upon a reduction in brake pipe pressure for supplying fluid under pressure to the brake cylinder, said means being operated by said abutments upon an increase in brake cylinder pressure to cut off the further supply of fluid under pressure to said brake cylinder, and yielding resistance means opposing movement of said abutments to operate said means for supplying fluid under pressure to the brake cylinder.

JOSEPH C. MCCUNE.

"Patent Office CERTIFICATE OF CORRECTION. Patent No, 2,088,550. July 27, 195?.

JOSEPH Ca MCCUNE.

It is hereby certified that error appears in the printed specification of the above nungbered patent requiring correction as follows: Page 8, first column line 51 claim 1h, after "means" insert the words operated by said abutments; and second column, line 51, claim 16, for "position" read opposition; and that the said Letters Patent should be read with these corrections therein that the same maj conform to the record of the case in the Signed. and sealed this 19th (Ila; of October, A. D. 1957.

Henry Van Arsdale. (Seal) Acting Commissioner of Patents. 

